Method of producing terpenes



Patented July 24, I934 sis-F- er-ct;

, 1,967,430 METHOD or rnonnomo 'rEaP N s J ohannes Rebner, Fin'ow, "near Ebe'rswalde, Ger

many, assignor to Schering-Kahlbaum A. (3.,

Berlin; Germany No Drawing. Application Decembe1y10, 1932, SerialNo'. 646,721. In Germany llecember, 18,

,- 9 Claims." (olrzsceiepfll or nopinene As has been shown in a copending application for patent of the United States Serial No. 527,846, filed April l, 1931 by Fritz Ulfiers and Rudolf Erbe, nopinene can be converted by catalytic action into pinene and camphene, or pinene into camphene, by acting on a material containing pinene or nopinene with catalytic quantities of an inorganic simple or complex acid or acid salt, which combine with the pinene or nopinene, if at all, only very slowly, forming in this latter case little stable addition products.

I have now made the surprising discovery, that this conversion of pinene and nopinene can also be brought about by the action of water-soluble neutral salts, especially the normal metal salts of sulfuric acid, which at temperatures up to 220 C. retain 1 molecule of water of crystallization.

These salts are distinguished from all other compounds hitherto used for this purpose by their solubility in water, whereby the further treatment of the reaction mixture can be effected more readily and at less cost, the catalysts being moreover recoverable, These salts can readily be obtained by crystallization and drying under ordi'nary or reduced pressure, their activity being a uniform one; l I I In. carrying out my invention .I may introduce these catalystsinto the liquid heated to the usual reaction temperatures ranging between 120 and 170 .C. in one or several portions and I may previously precipitatethese catalysts on inactive carriers. Alternatively, the oily starting material may be passed through a layer formed by such catalysts at a temperature somewhat below the boiling, point of the starting material or its vapors'maybe passed in contact with the catalyst; eitherby themselves or mixed with an-inert gas, at a temperature above the boiling point of the starting. material, viz.'at 160-30050, Instead of .pinene and nopinene also oils taining same may be used. 7 In practising my invention I may for proceed as follows:

instance Example 1 l kilogram pinene is boiled under the reflux condenser and 50 grams magnesium sulfate dried at 125 to 150 C. are added. After the pinene has disappeared, 200 ccms water are added, and the crude camphene, which has separated out, is treated further in a manner well known to those skilled in the art.

The dried magnesium sulfate (MgSO4.I-I2O) may be replaced by the corresponding sulfates of zinc, iron, cobalt, nickel or other heavy metals.

Example 2 Example 3 To 1 kilogram distilled oil of turpentine are added .under the reflux condenser 10 grams l\/Ig'SO4.H2O obtained from magnesium sulfate by drying in vacuo at 110 C. After a short period of time the reaction has come to an end and high-grade crude camphene is obtained.

Example 4 50 to 60 drops pinene are passed per minute together with a slow current of nitrogen gas through a tube 2 crns in diameter, which is filled for a length of 30 cms with MgSOnHzC precipitated on an inactive carrier substance and heated to 170 C. After a short time nopinene can be traced in the liquid leaving the tube. The crude camphene formed is treated further as usual.

Example 5 Terpene oil is allowed to flow slowly through a layer of granulated NiSO4.HzO heated to 120 to 130 C. The pinene soon disappears, camphene being formed, which is treated further in a well known manner.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention orsacrificing the advantages thereof.

I claim:

1. The method of producing terpenes comprising reacting, at a temperature ranging between 120 and 170 C. amaterial, containing a body of the group formed by pinene and nopinene,.with a water-soluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water of crystallization.

2. The method ofproducing terpenes comprising reacting, at a temperature ranging between 120 and 170C. a material, containing a body of the group formed by pinene and nopinene, with a wateres'oluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water of crystallization, this salt being precipitated on an inactive carrier.

3. The method of producing terpenes comprising introducing into a liquid body of the groupv formed by pinene and nopinene heated to a temperature ranging between 120 and 170 C. small portions of a water-soluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water of crystallization.

4. The method of producing terpenes comprising passing a body of the group formed by pinene and nopinene at a temperature above 120 C., but below its boiling point through a layer of a water-soluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water of crystallization.

A 5. The method of producing terpenes comprising passing vapors of a body of the group formed by'pinene and nopinene at a temperature above its boiling point in contact with a water soluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water; of crystallization.

6. The method of producing terpenes comprising passing vapors 'of a body of the group formed by pinene and nopinene at a temperature above its boiling point together with an inert gas in contact with a water-soluble neutral metal salt of sulfuric acid, which at temperatures up to 220 C. retains 1 molecule of water of crystallization. r I

7. The method of producing terpenes comprising passing vapors of a body of the group formed by pinene and nopinene at a temperature above its boiling pointtogether with nitrogen gas in contact with a water-soluble neutral metal salt of sulfuric acid, which at temperatures up to 220C. retains 1 molecule of water of crystallization.

8. The method of producing terpenes comprising reacting a body of the group formed by pinene and nopinene at boiling temperature with MgSO4.H2O.

9. The method of producing terpenes compris ing reacting a body of the group formed by pinene and nopinene at 140 C. with NiSOnHzO.

JOHANNES REBNER. 

